Tuning the mqweb server JVM

By default, the mqweb server Java virtual machine (JVM) uses platform-specific defaults for the minimum and maximum size of the heap. You might need to change the default values. For example, if a java.lang.OutOfMemoryError is thrown by the mqweb server, you must increase the maximum size of the heap. You should also increase the size of the heap if you are trying to load a large number of queue objects. You can change the default values in the jvm.options file.

Procedure

Open the jvm.options file.
The jvm.options file can be found in one of the following directories:
- On UNIX, Linux®, and Windows: MQ_DATA_DIRECTORY/web/installations/installationName/servers/mqweb
- On z/OS®: WLP_user_directory/servers/mqweb
  where WLP_user_directory is the directory that was specified when the crtmqweb.sh script ran to create the mqweb server definition.
Optional: Set the maximum heap size by adding the following line to the file:
```
-XmxMaxSizem
```
Where MaxSize specifies the maximum size of the heap, in MB.
For example, the following line sets the maximum heap size to 1GB:
```
-Xmx1024m
```
Optional: Set the minimum heap size by adding the following line to the file:
```
-XmsMinSizem
```
Where MinSize specifies the minimum size of the heap, in MB.
For example, the following line sets the minimum heap size to 512MB:
```
-Xms512m
```
Restart the mqweb server by entering the following commands on the command line:
```
endmqweb
strmqweb
```